$ { {-3} \times \left[\begin{array}{rr}{2} & {4} \\ {2} & {-2} \\ {-1} & {-2}\end{array}\right] = {?} } $
Answer: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{-3}\times{2} & {-3}\times{4} \\ {-3}\times{2} & {-3}\times{-2} \\ {-3}\times{-1} & {-3}\times{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-6} & {-12} \\ {-6} & {6} \\ {3} & {6}\end{array}\right]}$